Over objections from the White House and many science and environmental groups, the Republican-controlled U.S. House of Representatives this week approved two bills that would change how the Environmental Protection Agency (EPA) obtains and uses scientific data and advice. The bills aren’t likely to become law this year, but they are fueling an intense political battle that is likely to resurface when the new Congress convenes in January.

Proponents of the bills, which the House passed almost entirely with GOP votes, say they would increase transparency in how EPA uses data to justify its regulations and result in better, more balanced scientific advice for the agency. “EPA has an extensive track record of twisting the science to justify their actions,” and so reform is needed, said Representative Lamar Smith (R–TX), head of the House science committee, in a statement supporting one of the bills.

But opponents say the legislation would do more harm than good. “These bills are the culmination of one of the most anti-science and anti-health campaigns I’ve witnessed in my 22 years as a member of Congress,” said Representative Eddie Bernice Johnson (D–TX), top Democrat on the House science committee, in a statement.

White House officials say they would recommend that President Barack Obama veto the legislation if it reaches his desk. That’s unlikely in the current Congress, which ends next month, given that Democrats still hold a majority in the Senate. That makes the votes largely symbolic. But observers say they represent another salvo in a long-standing battle over the release of scientific data that underlines key regulations—and a sign of battles to come once Republicans assume control of both chambers of Congress in January.

One bill, approved 18 November on a mostly party-line 229 to 191 vote, would overhaul rules regarding the membership and meetings of EPA’s Science Advisory Board (SAB). That federally chartered body of scientists, economists, and other scholars reviews agency risk assessments and scientific documents and advises the agency on other matters. The EPA Science Advisory Board Reform Act (H.R. 1422), sponsored by Representative Chris Stewart (R–UT), would require the agency to make SAB’s membership “fairly balanced,” add more public comment opportunities, require more acknowledgment of dissenting panelists’ views, bar panelists from discussing their own research, and limit nonscientific advice from the panel. “Ensuring that the [board] is balanced and transparent will help instill more confidence in the EPA’s decision making process,” Stewart said in a statement.

The bill would seek to balance membership by setting a quota for state, local, and tribal government officials on SAB panels and clarify that industry experts aren’t barred from membership as long as their potential conflicts of interest are disclosed.

The second bill, the Secret Science Reform Act (H.R. 4012), would require that the data from any study that EPA draws upon to inform its regulations, risk assessments, and guidance documents be “reproducible” and released publicly as long as the law doesn’t forbid it. “If you’re going to make public policy, do it by public data,” said Representative David Schweikert (R–AZ), the bill’s lead sponsor and chair of the House science committee’s environmental subpanel, on the House floor on 19 November. The House approved the measure on a mostly party-line 237 to 190 vote.

Trade associations in key industries—from chemicals to oil to natural gas—support the bills, saying that boosting data transparency and changing SAB’s composition would result in more scientifically sound, and thus publicly trusted, regulations.

Opponents, however, say the bills are thinly disguised efforts to make EPA’s job more difficult.

For instance, the EPA SAB reform act could “turn conflict of interest on its head” by opening the door to more representation from industry scientists, says Andrew Rosenberg, director of the Center for Science and Democracy at the Union of Concerned Scientists, a science and environmental advocacy group, in Cambridge, Massachusetts. A White House statement argues that the new membership requirements “could preclude the nomination of scientists with significant expertise in their fields.”

Public health groups, scientists, and environmental groups warned in a letter to lawmakers that the bill would grind SAB to a halt by requiring an “endless loop” of public comment and responses from the panel to almost every comment. “At best, the SAB will be reduced to busy work. At worst, the SAB’s assessments will address the concerns of corporations, not the desires of citizens for science-informed regulation that protects public health,” the letter argues.

The “secret science” bill could drastically cut the number of studies that EPA would be allowed to use in developing rules, the advocates’ letter argues. By requiring “reproducible” data, the bill “seems to adopt a very narrow view of scientific information solely based on laboratory experiments,” it argues, noting that many studies that EPA traditionally relies on involve modeling or analyzing real-world health data, which can be hard to replicate.

H.R. 4012 could also rule out EPA’s use of other studies involving confidential health information, which can be important, critics say. And the bill’s requirements “could be used to prevent EPA from finalizing regulations until legal challenges about the legitimate withholding of certain scientific and technical information are resolved,” a White House statement warns.

Rosenberg argues that the real purpose of H.R. 4012 is to enable EPA critics to obtain data and turn it over to their own analysts, in order to pick apart studies they don’t like and produce findings more favorable to their views. “The problem they’re trying to fix is, they don’t like the answer” provided by certain studies, he says.

Both bills, or similar versions, are likely to resurface in the new Congress.